alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Win32/Qbot CnC Activity M2"; flow:established,to_server; http.request_line; content:"POST|20|/t4|20|HTTP/1.1"; bsize:17; fast_pattern; http.accept; content:"application/x-shockwave-flash, image/gif, image/jpeg, image/pjpeg, */*"; bsize:70; http.request_body; pcre:"/^[A-Za-z0-9]{3,20}=(?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=|[A-Za-z0-9+/]{4})$/si"; http.header_names; content:!"Referer"; reference:md5,3ceb36fc3607df3d67d9eb0f1d00fea0; classtype:command-and-control; sid:2035525; rev:2; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2020_12_09, deployment Perimeter, deployment SSLDecrypt, malware_family Qbot, performance_impact Low, confidence High, signature_severity Major, updated_at 2020_12_09;)